55821285 has 64 divisors (see below), whose sum is σ = 113218560. Its totient is φ = 25850880.

The previous prime is 55821277. The next prime is 55821287. The reversal of 55821285 is 58212855.

55821285 is a `hidden beast` number, since 558 + 21 + 2 + 85 = 666.

It is not a de Polignac number, because 55821285 - 2³ = 55821277 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55821287) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 28900 + ... + 30770.

It is an arithmetic number, because the mean of its divisors is an integer number (1769040).

Almost surely, 2^55821285 is an apocalyptic number.

It is an amenable number.

55821285 is an abundant number, since it is smaller than the sum of its proper divisors (57397275).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55821285 is a wasteful number, since it uses less digits than its factorization.

55821285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1915 (or 1909 counting only the distinct ones).

The product of its digits is 32000, while the sum is 36.

The square root of 55821285 is about 7471.3643332393. The cubic root of 55821285 is about 382.1788153446.

The spelling of 55821285 in words is "fifty-five million, eight hundred twenty-one thousand, two hundred eighty-five".